Theory and practice of multicomponent composite bl

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Theory and practice of multi-component composite blending modification of plastics

I. overview:

plastics, as a new man-made material, are widely used in all walks of life of the national economy and people's life. Generally, the raw materials of plastic products are made of pure resins, such as PE, PP, ABS, etc. With the development of modern science and technology, higher requirements are put forward for the performance of plastic materials, and pure resin is unable to meet its needs. On the contrary, adding various non-metallic and metallic materials to pure resin can improve the performance of plastic resin to achieve the required technical indicators and high property price ratio. Among them, non-metallic materials, such as CaCO3, talc powder, wollastonite powder, mica powder, etc., are the most used. Plastic modification processing is wonderfully combined with non-metallic minerals, powder processing, ultra-fine grinding and other industries, which has promoted the development of plastic modification. Since human society entered the 21st century, focusing on the processing and modification of modern plastics, a comprehensive industrial chain has been formed, which is dominated by plastic resins, supplemented by various additives and processing aids, various plastic forming and processing machinery, chemical synthesis, steel production and processing and other processing industries

the purpose of early plastic modification was mainly to reduce product cost. Calcium plastic molding in the 1970s was a famous example; Since the 1980s, some specific properties of plastics have been improved, such as flame retardant modification, antistatic, glass fiber reinforced modification, biodegradation and photodegradation; In the 1990s, plastic modification mainly focused on improving the mechanical and physical properties of pure resin and the continuous improvement of treatment methods; During this period, the varieties of compatibilizers and coupling agents were expanded and the efficiency was enhanced. The plastic processing machinery also developed from single screw extruder to twin screw extruder and reciprocating single screw extruder. It is worth mentioning that China is a developing country producing plastic products, and many plastic blending modification projects are ahead of the world; For example, the quality of CPVC pipe fittings developed by Mr. xiaoxianghua exceeds that of similar Japanese products, and the price is lower than that of Japanese products; Another example is the carrier free flame retardant masterbatch developed by the author and exclusively produced at home and abroad, which has reached the world leading level; The reason is that almost all the synthetic processing of plastic resins in China are produced with imported equipment, and the latest and best core technologies are not in the hands of the Chinese. Compared with foreign countries, the resin brands produced in China are few and the quality is relatively poor. "The deficiency of nature first and the remedy of nature later", which instead promotes the vigorous development of the cause of modified plastics in China

the surface modifier of inorganic powder materials filled and modified in the early stage has received certain effects from stearic acid to coupling agent, and the coupling agents include silane, titanate, aluminate, borate, phosphate, etc. After entering the 21st century, with the increasing requirements of modern science and technology for plastic materials, the plastic modification technology has already jumped out of the classic coupling surface treatment powder theory. The generation of elites in plastic modification all over the country have launched their own scientific research achievements and modification theories, The brief introduction is as follows:

1) inorganic rigid particle toughening theory

2) nano materials and whisker toughening and reinforcing materials

3) coupling agent and auxiliary coupling agent theory

4) chemical connection technology, chemical crosslinking

5) rare earth coupling agent

6) organic inclusion and ternary blending theory

7) elastomer toughening technology

8) blending of different substrates Compatibilizer theory

9) liquid crystal in-situ composite technology

10) in-situ combined chemical modification of powder surface

11) microencapsulation

12) utilization and modification of waste plastics, supercritical water degradation of waste plastics

13) engineering and alloying of general plastics

14) inorganic powder modified plastic environmentally friendly materials Wood plastic composites

especially at the annual meeting of the modified plastics professional committee of China Plastics Processing Association in October 2003, China's contemporary plastic modification elites, professors and experts took the stage one after another to introduce the latest and best modification theories and practices since the beginning of the 21st century, presenting a new situation in which a hundred flowers bloom and a hundred schools of thought contend. For example, Professor Zhang Wengong's theory of "in situ combined chemical modification of powder surface" and liuboyuan's viewpoint of "a+b+c+d" and "post coupling agent era" [1]. This fully shows that in a certain historical period, when the technology has developed to a certain extent and there is a certain social demand, there will be corresponding development technologies to appear, summarize, promote and apply

In April, 2004, the author received a task of "special material for flame retardant cast polypropylene film with high tear resistance". The technical indicators are: film width 2m, thickness 20-500 μ m. The flame retardant performance reaches UL94 standard class V-0, the tensile strength is ≥ 32Mpa, the tear resistance is ≥ 170kn/m (longitudinal and transverse), and the appearance is milky white and translucent. The simple test method is that no matter who uses the maximum force to tear the film manually, it cannot be torn. People familiar with flame retardant PP know that in flame retardant PP, due to the addition of flame retardant in PP, its physical and mechanical properties have decreased to varying degrees. However, the technical performance requirements of the material have almost no room for decline, and the technical difficulty is great. It has always been produced with imported raw materials. Based on my more than 30 years of experience in flame-retardant plastic modification and plastic molding processing, and absorbing the experience of the elite masters of plastic modification at the 2003 annual meeting of the modified plastics professional committee of China Plastics Processing Industry Association, the author summarized the plastic multi-component composite modification theory of duo=1+2+3+... +n, and carried out the development and development of the project. The project was successful in only four weeks. After the user tried it out, the effect was good, and all indicators met the technical requirements, Directly replace imported products. However, if the project adopts the common conventional trial production method, it will take one year from data collection to successful trial production [2]

in late August, 2004, liuboyuan senior engineer proposed to the author to develop a master batch for strengthening, toughening and strengthening large-diameter buried pipes in Shanghai [3]. We received the support of Mr. wangzigang, chairman of Shanghai Linda Plastic Chemical Co., Ltd. after repeated and enthusiastic discussions and exploration, under the guidance of the latest plastic modification multi-component composite blending modification theory, the trial production was successful in only more than one month. According to the test conducted by the testing department of Shanghai Shengde plastic factory, while improving the ring stiffness of the material, other technical indicators remain basically unchanged, or even improved, which is a new breakthrough

II. Theory of plastic multicomponent composite blending modification:

based on the experience of contemporary elite masters of plastic modification, the theory of plastic multicomponent composite blending modification states that the surface treatment of processing aids (fillers, tougheners,...) in modern plastic modification is not the same as that in the past, for example, only titanate or silane coupling agent is used for surface treatment, This kind of surface treatment has been difficult to meet the higher requirements of the rapidly changing high and new technology for plastic materials. The diversified composite surface treatment of duo=1+2+3+... +n can be adopted to meet the higher requirements of technology, quality and processing technology; At the same time, a variety of processing aids, such as fu=a+b+c+... +n, are compounded according to different application occasions and different technical index requirements. Only in this way can the modified plastics meet the users' stringent requirements for modified plastic materials, or one or two technical indexes are greatly improved while other indexes remain basically unchanged, or the cost is greatly reduced on the premise of ensuring quality, so as to better participate in market competition. Here, duo means diversified treatment and Fu means composite blending

III. application of the theory of multi-component composite blending modification of plastics in Digitalization:

for many years, scientists in various countries have been trying to apply computer technology to their own scientific experiments and production practices, but the development of new varieties of modified plastics is an applied science, that is, we must first carry out exploratory formulas, then make samples through field trials, then test according to standards to obtain scientific data, and then screen out reasonable formulas, Trial produce finished products and further improve them to produce new and reasonable scientific theories to guide practice. As a Chinese plastic science and technology expert, he has always dreamed of using computer technology to simulate plastic modification experiments to improve work efficiency and complete the project more quickly, better and economically. At the same time, if there is an advanced theory to guide the promotion of analog plastic modified digital technology, it will benefit the majority of small and medium-sized plastic enterprises. It will no longer be unable to implement modified plastics due to lack of technical force, thus saving time, effort and money. However, the digitization of plastic modification technology has been stranded due to the lack of appropriate theoretical and mathematical models and digital tools. The emergence of the theory of multi-component composite blending modification of plastics has found a way to combine the plastic blending modification technology with computer application. It has provided a platform for us to transform the latest theory of plastic blending modification into advanced production technology and guide scientific experiments and production practices; Its application can make a certain performance of the modified plastic excellent, while other performance and technical indicators do not decline, and the original processing technology and processing equipment do not need to be changed

the most important thing here is to establish an approximate conversion relationship model between the hardness value and tensile strength value of several materials after the success of the plastic degradation film experiment and the implementation of the multi-component composite blending modification theory, so as to facilitate the organic combination of the computer simulation plastic modification technology and the general plastic or engineering plastic formulation technology. The representative formulas are duo=1+2+3+... +n and fu=a+b+c+... +n. Duo and Fu mean multi-component composite blending, 1, 2, 3 ..., n means there are n surface treatment methods, and a, B, C,..., n means there are n kinds of processing aids for composite blending. Of course, the establishment of the mathematical model must also have the corresponding digital method sampling. Here, we grasp one or two main factors and use the optimization method (multi factor) proposed by the famous mathematician Mr. Hua Luogeng to extend the long-term popular golden section method at home and abroad to the two factor treatment, with a value of 0.618. Because its value is difficult to remember and calculate, it is difficult for people with low educational level to correctly use it in actual trial production. In the long-term trial production, we appropriately adopted the half method. We launched the monprene in ⑵ 3000 series SBC composite material, which is convenient for memory and actual calculation, and has a low error rate. However, the trial production times are only about 3~5% higher than that of the golden section method, so it is a method with more speed, better economy and less errors. Of course, there are still many problems and difficulties waiting for us to overcome in the process of compiling relevant computer software. Here, we warmly welcome all colleagues in the same industry to call and write to join us, exchange and learn from each other, so as to better integrate the plastic multi-component composite blending theory with the digital actual development and production, guide the industrial development and production, so as to achieve less development time, reasonable production formula, complete and effective production process, low production cost and stable product quality. This is a great good thing to promote the development of plastic modification

IV. practice of plastic multi-component composite blending modification theory:

plastic multi-component composite blending modification theory has opened the thinking horizon of scientific researchers. It can complete the trial production in a small amount of time in the past, which can not only save the trial production cost, but also digitize the plastic trial production and production, and realize computer management. So as to improve labor productivity, reduce costs, ensure product quality and enhance the gold content of product technology. The "special material for high tear resistance and flame retardant cast polypropylene film" developed and produced under the guidance of the theory of multi-component composite modification of plastics has obtained

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